Meconium - NICUvetnicuvet.com/nicuvet/Equine-Perinatoloy/Lecture Notes...Asphyxia, Sepsis Meconium...

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Meconium

Meconium and “milk feces”

Meconium

Meconium is formed from Swallowed amniotic fluid Intestinal secretions (e.g. bile) Cellular debris Other debris

Appears during the 1st trimester Accumulates throughout fetal period Bile acids

Excreted by the beginning of 2nd trimester

Meconium

Concentration of bilirubin in meconium 50 times that of the serum

Intestinal absorption of bilirubin Icterus in the neonate

Dark color of meconium due to bilirubin pigments If meconium retained

Its color becomes the same as "milk feces” Bilirubin pigments will be absorbed/ excrete in urine

Meconium

In utero meconium passage Associated with fetal distress ? Can occur as early as the 2nd trimester Late term meconium passage

Fetal GI innervation matures Defecation controlled by parasympathetic stimulation Vagal stimulation with cord or head compression

In utero Meconium Passage Fetal diarrhea

Born passing profuse, liquid meconium

Resolves within 48 hours of birth

Associated with intrauterine insults Hypoxia/asphyxia

FIRS/sepsis

Manifestation of fetal enteritis?

Meconium Impactions

Increase incidence in colts Narrow pelvic canal

Excessive meconium formation Impaired GI function

Asphyxia, Sepsis

Meconium retention Prematurely/Postmaturity Prolong recumbency Dopamine

Meconium Impactions Signs

Strain to defecate - arched back Nurse frequently

Not effective Dried milk on head

Persistent colic Rolling on back Kicking at abdomen Frantically swishing tail

Urination

Defecation

Meconium Impactions Signs

Abdominal distension

Tenesmus

Umbilicus may reopen

Bleed

Drip urine

Meconium Impactions Diagnosis - History

Foal "past his meconium"

Variable amount in each foal

Passage of meconium easily missed

Little or no meconium passed & colic

Meconium Impactions Diagnosis - Physical Examination

Digital rectal examination Rectal mucosal edema

Enema can be diagnostic

Deep abdominal palpation Meconium is distinct

Caudal abdomen

Anterior abdomen

Abdominal ultrasound

Meconium Impactions Differential Diagnosis

Ruptured bladder NEC Intussusception Intestinal volvulus Rectal perforation Colonic atresia Lethal White Syndrome

Meconium Impactions Treatment - Enemas

Soapy water gravity enemas Rectal irritation - persistent tenesmus

Lubricant enemas Dioctyl sodium sulfosuccinate (DSS) enema Glycerin enemas Retention enemas

4% Acetyl cysteine Rectal distension - stimulates motility Add barium - osmotic effect (MOM)

Acetyl Cysteine Retention Enema

Acetyl Cysteine Retention Enema

Meconium Impactions Treatment - Oral Laxatives

Colostrum

Mineral oil

Milk of magnesia

DSS

Castor oil

Meconium Impactions Supportive Care

If impaction prolonged Intravenous fluids with dextrose

Continue nursing?

Close attention to adequate passive transfer Higher risk for sepsis

Damaged colonic epithelium

Open umbilical structures

Plasma transfusion

Meconium Retention

Neonatal Gastroenteropathy Dysmotility Meconium retention

Signs Not passing meconium No abdominal pain No distension Retains enema fluid

Duration 4-8 days As long as 30 days

Birth Trauma

Rib Fractures Physical Examination

2 - 4 cm above costochondral junction Involving 4 to 12 ribs in a straight line Any rib or set of ribs may fracture

Most frequently anterior chest (ribs 2-8)

Over the heart Palpation - feeling click Auscultation - click associate with heartbeat Easily confirmed on radiographs, ultrasound

Rib Fractures Hemorrhage

Primarily bleeding from intercostal arteries

Most often diffuse chest wall/subpleural/hemothorax

May be extensive - not evident externally

Lung contusions - hemothorax

Lacerations of the myocardium

No pericardial damage - Cardiac tamponade

Arrhythmias

Trauma to other structures

Rib Fractures Clinical Signs

Signs are variable From pain, anemia, cardiac arrhythmias

Tachycardia Tachypnea

Positional Exacerbated during examination Exacerbated when down Weak, minimally responsive foal

Distressed when on one side - relief when turned Exacerbated of hypotension when turned

Umbilical Problems

Umbilical Bleeding

Can be a major source of bleeding

External (extracorporeal) bleeding

Internal umbilical artery ruptured Commonly in calves, rare in foals

Large hematomas

Bleeding contained within fascia

Umbilical Bleeding Umbilical Artery

Body Wall Hematoma

Umbilical Bleeding Umbilical Artery

Artery pulls back into umbilical stump Attendant squeezing end of the stump

Not effectively stop bleeding Umbilical clamp or umbilical tape

Not effectively stop bleeding Leaking blood

Travel along fascial planes Body wall hematoma Internal hematoma

Flow through the urachus Large hematoma free in bladder Hematoma along the urachus

Umbilical Bleeding Umbilical Artery

Often clinically inapparent Pass bright red urine within hours of birth Occasional urinary obstruction - organized clot

"pop-off valve" - urachus becomes patent

Body wall hematomas - secondary edema Diagnosed by careful abdominal palpation

Sleeping or weak neonate Can be as accurate as ultrasound Find bladder/urachal hematomas - no clinical signs

Umbilical Bleeding Umbilical Artery

Some foals - extensive bleeding Hemorrhagic shock

Most foals do not bleeding extensively Signs of urachitis - persistent straining to urinate Asymptomatic

Icteric Mildly anemic

Patent Urachus

Patent Urachus

Most often seen 3-5 days old When umbilical “scab” falls off

Diagnosis Observe urination Wet between or constant leak Beware colts – not drop penis

Treatment Benign neglect Antimicrobials? Avoid topical therapy Do not suture

Urachitis Urachal disease

Infection Hematoma Delayed atrophy

Signs Straining to urinate after normal urination Repeat posturing

Consequences Usually none Patent urachus

Therapy Benign neglect Phenazopyridine (Pyridium)